Tenn. Code Ann. § 66-11-103

When the contract for improving real property is made with a husband or a wife who is not separated and living apart from that person's spouse, and the property is owned by the other spouse or by both spouses, the spouse who is the contracting party shall be deemed to be the agent of the other spouse unless the other spouse serves the prime contractor with written notice of that spouse's objection to the contract within ten (10) days after learning of the contract.